Moving-pivot technique

Kumar, S. and Ramkrishna, D., 1996b. On the solution of population balance by discretization IE A moving pivot technique. Chemical Engineering Science, 51, 1333-1342. 

Let us start by discussing the implication related to the choice of a particular discretization and the restoration of autonomy for second-order point processes by using two different approaches the fixed (and moving) pivot technique and the cell-average technique. If represents an additive property of the particle (e.g. the particle mass), the source term for a second-order point process is... 

This moving-pivot technique is different from QBMM, which will be introduced later in Section 7.4. In fact, in QBMM the pivots or nodes of the quadrature approximation are free to move not only in the interval / , but also in phase space, conferring greater flexibility on the method. 

FIGURE 4.5.2 Comparison of the fixed and moving pivot techniques of Kumar and Ramkrishna (1996b) on the solution of the aggregation problem for the sum kernel with its analytic solution. Reproduced with permission from Elsevier Science. 

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